<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<ul>
    <li>111</li>
    <li>222</li>
    <li>333</li>
</ul>

<script src="jquery-3.2.1.min.js"></script>
<script>
    $("li").click(function () {
        alert(1234)
    })
</script>


</body>
</html>